OG wrote:
So, after the long discussion on smoke detectors I thought it best to
start a new post hole.

I opened the case and looked at the board.
It is a so called military grade MSI ATX motherboard.
I saw no charred anything.
But I did see pieces of charred something sitting on the board and
looked upwards and discovered a cable hanging loose.

Look closely at the end of the cable and saw what was left of a drive
power connector. Traced that to the power input to a Hitachi 2T HDD.

What that my C: drive (Win 7) ? Yikes!
I have four 2T drives in there.
Thank goodness I just backed up the C: drive using Macrium Reflect Free
to an external USB Drive.

Anyway, now I am wondering if the power supply was taken out.
It is a 600W CoolerMaster RS-500-PCAR.
Do these protect themselves or just melt down with the connector.
The cabling is hard ot get to since the PC is packed tight with 4 HHD
and two DVDs and a few boards plugged into the motherboard.

So maybe the connector contact was not so good and the resistance
increased to a point where the connector melted the shorted out?
The connector was melted AND also turned to dust.

Connector went bad or ?

Wonder if the drive is still good.
Got to take it out and have a good look.

Thoughts (other than smoke detectors).

I would not trust the connectors now.

That means replacing the power supply.

If, on the other hand, the connector was a SATA Y-cable
or a SATA extension, maybe that was the defective part,
and the power supply doesn't have a quality issue.

If the power supply connector end burned, you cannot
use that drive again. The contacts on the drive end,
will be heat-damaged and degraded, and will encourage
the connector on a new supply, to fail in exactly the
same way. You may be able to connect the drive long
enough to clone it, but I would no longer trust it.

When the connector is new, the metal is nice and shiny
and conductive. After an overheat issue, the metal
is oxidized, heat stressed, and has a higher resistance.
Replacing both ends of the connector system, is required
to return things to mint condition. And that's why you
shouldn't use that hard drive again.

If you do want to use the hard drive again, you can use
an extension cord. When it burns the extension cord,
there would be no damage to the new power supply.

PSU ----- Molex to SATA ----
---- - - - Bad drive

^
|
+--- Will burn here...

So if it were to burn again, just the middle
(extension cable) would need to be replaced.
It all depends on whether you like the smell
of "resistor smoke", as to whether that is
a practical alternative (isolates the damage
a bit better). The second time it fails,
will be for potentially different reasons
than the first time, due to the heat
damage to the drive end power contacts.

You can easily solder a pigtail to the hard drive,
to power it in place of the SATA 15 pin. So even if
you didn't have backups, you may be able to get
the data off it. It would require locating where
+5V, +12V, GND, GND are on the controller board,
to tap in and connect a Molex pig tail as a replacement.
I did that to replace a burned end connector on a
video card and it held up fine.

*******

One suggestion here is "tin whiskers". A metallurgy
problem. You cannot use pure tin on assemblies,
because a thin spike of material will "grow" between
conductors. The whisker grows between conductors,
until it shorts them out.

https://community.spiceworks.com/top...lted-smell-bad

We had some special RAM modules we designed at work.
The first ones, were made with gold all over the place.
At the time, gold wasn't nearly as expensive as it is
now. Anyway, in the spirit of cost-reduction, the
next generation (same form factor), they decided
it would be fun to make them with tin in place of the
gold. And apparently, the person who did that, had never
heard of tin whiskers. And pretty well exactly one year
to the day, each module would fail, as a whisker would
grow across the surface of the substrate. We used to
run an Xacto knife between tracks, to cut the
whiskers, but they would only grow back again. Making
the RAM modules a write-off. The substrate in this case
was ceramic, so these were not even remotely close
to modern DIMMs or SIMMs in design. A thorough
understanding of metallurgy is required for
anyone doing this sort of design work (i.e. don't
ask me to do it :-) )

Metallurgy affects lots of stuff. When you see electrical
contacts on things, they consist of a number of layers
of plating. The materials and order of layering is
determined by safe metallurgy. So you could use tin,
if it was combined with the correct other materials.
So someone knows what metal mixture, plate up, or whatever,
will stop whiskers. There's no need for whiskers in
electronics in 2016. This is "all known stuff". You
shouldn't be designing connectors and cables, unless
you know this stuff.

Paul